ST_Reverse documentation should mention no support for M values

[pauldzy]

ST_Reverse strips off M measure values.

This should probably be mentioned in the documentation for the function.

Thanks, Paul

[robe]

hmm strk, pramsey is there a reason why ST_Reverse strips M? I thought this is an in-built function and would in my mind, just walk the point array in reverse direction.

[strk]

Really no reason. I'd call it a bug if that's the case. But is it ?

strk=# select st_asewkt(ST_Reverse('LINESTRING M(0 0 0, 1 1 1)'::geometry));
        st_asewkt         
--------------------------
 LINESTRINGM(1 1 1,0 0 0)
(1 row)

[robe]

ah yes even in my 2.1.8

POSTGIS="2.1.8 r13780" GEOS="3.5.0-CAPI-1.9.0 r4088" PROJ="Rel. 4.8.0, 6 March 2012" GDAL="GDAL 1.11.1, released 2014/09/24" LIBXML="2.7.8" LIBJSON="UNKNOWN" RASTER

(and the sT_AsText) returns the ogc preferred.

SELECT ST_ASText(ST_Reverse('LINESTRING M(0 0 0, 1 1 1)'::geometry));

         st_astext
----------------------------
 LINESTRING M (1 1 1,0 0 0)
(1 row)

Paul,

Can you provide the

SELECT postgis_full_version();

you are seeing the issue and also which particular query you are running where you are not seeing your M come back?

[pauldzy]

I indeed have to apologize. I cannot reproduce this now either. It seems I may just have imagined the whole thing. I convinced myself of this issue enough to even write my own quick line reverser…

Sorry for wasting your time, feel free to delete the ticket.

Paul